Do you think        necessary to do a bird count ?Yes , we must count them at least once a year 

—Who helped you repair your bike?—________ ! I repaired it all by myself.

—Is the girl in the red skirt your sister?—No. She is____ classmate.

Mr Brown taught ________ math when we were in Junior One.

 There are two new buildings near the sea, and ____of them are very tall.